Furnace grate structure, including ash removal means



W. F. PFAU Sept, 18, 1951 FURNACE GRATE STRUCTURE INCLUDING ASH REMOVALMEANS Filed Dec. 15, 1947 an ll INVENTOR. WILLIAM E PFAU BY Dl-EJARDINS,ROBINSON KEISER HIS ATTORNEYS Patented Sept. 18, 1951 UN 'IiTE 'l) PATENT QFFIiC Ei ormica GRA'TE' STRUCTURE, INGIQUDING asHRE ovAnMEAN-sWilliam-"E; Pfau, Norwod-,,0hio Applicationfie'cemlierili 1947; sesame.-791,859

4:16laims. (01. 1130-36):

This invention relat'esi-to a novel and improved combustion device' irrwhichselid fuels; such ascoal, c'oke -or the like, are'burned'inheatingand cooking stoves, boilers-or furnaces, moreparticularly of the 'types used-in small homes I and dwell ings; Theimproved device provides aneflicient combustion. chamber." to which thefuel is-fed tobe completely burned; and the ash residue is removeddn;anLeVen-and uniform: flow in continuity witlrthefl'ow of:thetfuelthrough the combustion chamber.

The: inventionip'ertainsrparticularly" to a circular. grate: formedfromaseveral superposed circu larfrings: disposed to-prov-ide.acombustiomchamberr above. an; oscillating plate which serves as thebottomfor' the combustion; chamber; Ilever: arms are; provided. on the:top: of the oscillating; plate to be: manipulated". relatively 'torthe.plate: whereby theashresidue is removed continually from thebottom ofthEcomb'ustionZchamber an'di over the edge of the plate wherelitlcank'be col= lected and removed; The lever arms form a U- shaped pocketor chamber in the bottom of the combustion chamber, and, when oscillatedrelatively to and with theplate, they continually push the ash residueout of the open side of the U-- shaped pocket or chamber to an ashreceptacle or remover;

For a. better understandingof the invention, referenceis made.totheaccompanying drawings inzwhichti Fig. I is1a verticalcross-sectional view of the device embodying the invention.

Fig. 2 is a horizontal cross-section on line 2-2 of Fig. 1.

Referring to the drawings in which like numerals are used to designatelike parts, numeral I is a base or foundation of a furnace bowl 2 ofconventional design. A refractory ring 3 is supported on a ledge 4,preferably integral with the bowl, in the furnace above a grate composedof grate rings 5 with the bore of the refractory ring registering withthe bore of the grate rings. There are any number of superposed graterings to build up a fire box or combustion chamber of any desired depth.Knobs 5a may be formed at spaced intervals on the top or bottom edges ofthe grate rings to contact with the adjacent rings to provide air spacestherebetween. The grate rings are supported by means of any number oflegs or brackets 51) which are attached to some fixed part of thefurnace, such as wall 6 or the base I, or the bottom ends of thebrackets or legs may be fixed to the plate I as shown. When the legs orbrackets are fixed to some fixed 2- part ofthefurnace, such as base I orside wa'll 6; the grate rings are supported entirely in dependentlycf'the plate I, and this facilitates insertion-and removal of theoscillating plate unit. However; when the-legs -or bracekts are fixed totheplate 'f', thegrate ringswill be oscillated withthe-plate to-furtheragitate the contentsof the combustion chamber. About three or more ofthes'elegs orbrackets, spaced apart, are-sufficient for supporting thegrate rings,

The' pl'ate"! is-movably mounted-upon the baseor foundation- I by meanso-fa-bearingunit 8, prefer-ably an anti friction one, intl-zrpose'd between the foundation and the plate: This bearin'g may. Ice-anyconventional roller or ball bearing withtherollers: or balls 8ainterposed betweent'woraceways 8-1;. A center stud 9isadvantagecusl ypro-vided; if desired, as a pivot for holdingthepl'ate'i centered;although the bearing alone may sufilce to keep the plate centered,particu larly if the raceways be fixed respectively'toi the base and'the plate a's' theymay be by spot .welding;- The studcan be fixedleithertos therfcnndae tionorthe plat'e by any suitable means such. welding,andi is' of a: diameter to th'ezboren of the"- raceway ringszof theibearing;

Two: arms 15!]. are eaclit pivoted1to the top. sideof the plate! bymeans ofaawstudzshaft. H cfixed to'zthe plate: TheLarms-Jare/duplicates,- and are: oppositelyfdisposed'with'thezcurvedends l2iabut'. ting and: the main portions of the {arms s'parallell. Theinside. edge. surfaces 13- of the ncurvedends; are arcuate, and,v withthe'main -portions of: the: arms, they form a U-shaped member on the topof the plate to provide a U-shaped pocket or chamber for the bottom ofthe combustion chamber. The ends of the arms opposite to the curved endsare pivoted at 14 to a cross piece l5 which in turn is pivoted at I6 toa cross support [1. The ends l8 of the cross support may be fastened tothefurnace wall 5 by any suitable means, such as bolts Hi. This crosssupport thus firmly holds the plate unit in position.

The arms, as well as the plate to which they are pivoted, are oscillatedby a prime mover, such as motor 20, which is attached to the arms by anysuitable power transmission mechanism. This mechanism may advantageouslybe a link 2! pivoted at one end to the cross piece [5 or to one of thearms at M as shown. The link is pivoted at the other end by stud 23 on acam 24 which is attached to the motor shaft.

As the arms are oscillated from the full to the dotted line positions,their arcuate inner edges will work the ash residue towards the opposite3 side of the plate and over its edge where it gravitates to an ashremover 25, the ash remover being typified by a screw conveyor.

In order to prevent any ashes Working between the curved ends of thearms, their outer end surfaces 26 are diverged to provide a triangulararea which can be partially or completely filled by a triangular piece21 which is attached to the upper surface of the plate.

A front door 28 can be provided as shown in the wall of the bowl of thefurnace to permit the unit being inserted in and removed from thefurnace. The door can have an air draft regulator of conventionalconstruction for letting in or shutting out the air.

The furnace may be hand fired or mechanically fired with a screwconveyor 29 disposed to discharge a supply of fuel into the furnace atthe top of the combustion chamber. If mechanically fired, the necessaryautomatic thermostat controls may be used, but these are, of course,conventional, and may be used or not, as desired.

The device is simple in construction and may be readily installed as aunit in any conventional coal-burning furnace] It lends itself to handor mechanical firing and moves the coal evenly through the combustionchamber where all parts are exposed to air mixture so that combustionwill be complete. As the ash residue is removed, the fuel in thecombustion chamber is slightly agitated and is moved uniformly towardsthe U-shaped chamber in the bottom where the ash residue is alsouniformly removed to an ash containeror collector.

While I have illustrated and described one preferred embodiment forcarrying the invention into effect, it will be understood that there maybe various changes in details of construction without departing from thespirit of the invention.

I claim:

1. A combustion device for burning solid fuels 4 the bottom of thecombustion chamber over the surface of the plate.

2. A combustion device for burning solid fuels comprising a fire boxforming a combustion chamber, a plate beneath the fire box and disposedhorizontally for supporting the solid fuel thereon, a bearing formovably supporting the plate, a pair of lever arms having curved endsand pivoted intermediate their length to the margin of the plate inspaced apart relation with the curved ends of the lever arms adjacenteach other to form a U-shaped wall in the bottom of the combustionchamber around the top surface of said plate, and means for oscillatingthe plate and lever arms for causing said lever arms to push thecontents of the bottom of the combustion chamber out of the U-shapedopening resulting from the U-shaped wall.

3. A combustion device for burning solid fuels comprising a fire boxforming a combustion chamber, a plate movably mounted beneath the firebox, a pair of lever arms having curved ends and pivoted intermediatetheir length to the plate in spaced relation with the curved ends of thelever arms disposed adjacent each other to form a U-shaped pocket in thebottom of the combustion chamber above the plate, and means foroscillating the lever arms relatively to the plate for causing same topush the contents of the bottom of the combustion chamber out of theopen end of the U-shaped pocket.

4. A combustion device for burning solid fuel comprising a fire boxforming a combustion chamber for burning the solid fuels, a movablehorizontally disposed plate beneath the fire box for supporting thefuels in said fire box, a lever pivotally supported intermediate itslength to said plate with one end thereof in position to be movedadjacent to the top surface of the plate for pushing the material withinthe fire box toward one edge of the plate.

WILLIAM F. PFAU.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 753,793 Gorman Mar. 1, 19041,112,702 Jefferies et a1 Oct. 6, 1914 1,194,730 Glover et a1 Aug. 15,1916

